Intelligent network (IN) or advanced intelligent network (AIN) provide mechanisms to create and support uniform telecommunications services. Intelligent network elements, tied together with signaling system no. 7 (SS7) or common channel signaling no. 7 (CCS7) provide an infrastructure to deliver a variety of new telecommunications services. Such signaling systems exchange transaction capabilities application part (TCAP) messages or queries between network elements to invoke selected services and ISDN-user part (ISUP) messages between network node switching elements to set up and route calls. The TCAP and ISUP messages are handled by a data communications system separate from the trunks which carry the calls themselves. The elements of such intelligent telephone systems include service switching points (SSPs) interconnected by trunks for carrying calls, and signal transfer points (STPs) and service control points (SCPs) connected to each other and the SSPs by SS7 data links for carrying signaling. A service control point (SCP) is an “intelligence center” with access to application databases enabling it to deliver various combinations of features, such as 1-800 number services and call redirection. A signal transfer point (STP) is a signaling hub or concentrator, typically connecting several service switching points to an SCP. A service switching point (SSP) is a network node normally associated with central office switch equipped with signaling system number 7 (SS7) messaging links to permit communication with the SCPs and which has special IN call processing software including a plurality of “Point-in-Call triggers” which can be provisioned or set to interrupt call processing momentarily and initiate a TCAP query to the SCP for instructions on how to complete the call processing. Based upon the instructions, the originating end office seizes a trunk to a neighboring switch and creates an initial address message which it sends to the neighboring switch via the signaling network. The initial address message includes various parameters which will control routing of the call to its destination.
Some services provided by AIN include, for example, intelligent caller data, disaster routing, call screening, automatic callback, and intelligent call redirection. Intelligent call redirection involves assigning a number to a subscriber by which callers may contact the subscriber at different locations or telephones. In this case, a telephone number is assigned to a specific person rather than to a physical telephone. When a call is made to a subscriber's telephone number, the call is routed to a telephone at one of a number of locations. If the user cannot be located at one of the locations, the call may be routed to a voice messaging system. Further, the call also may be routed to a cellular telephone or a pager. The primary difficulty in effectively implementing personal telephone numbers involves accurately determining to which physical telephone instrument to forward calls.
One approach in locating a subscriber follows a “find me” approach which typically forwards calls to a personal telephone number to different telephones according to a preset sequence until the subscriber is located. This approach involves defining the potential location of a subscriber and routing the calls to a telephone where the subscriber may be found at a particular time. One problem with this mechanism is that a subscriber may not keep a rigid schedule resulting in delays in finding the subscriber. These delays are caused because the caller must wait while the system rings each telephone number in the sequence three or four times before proceeding to the next telephone number if the subscriber does not answer the currently called telephone number.
Another approach involves a “follow me” approach, which forwards calls to a personal telephone number according to recent activity of the subscriber. This activity includes the subscriber engaging in credit card calls, credit card transactions, or automated teller transactions indicating the location of the subscriber. When such an activity is performed, the location of the individual, potentially including the telephone number, is recorded in a database that tracks the location of the subscriber. Calls can then be forwarded to the specific telephone number associated with the last known location of the subscriber, or to the telephone number in the subscriber's defined list of calls that is nearest to the last known location as indicated by the area code, cellular region, paging area, etc.
One problem with this approach is that it provides a forwarding location for calls to a personal telephone number that may be available for only a limited time. The new number is valid only as long as the subscriber stays at the location where he performed that activity.
Therefore, it would be advantageous to have an improved method and apparatus for locating and calling a subscriber having a telephone number that is routable to a number of different locations.